Saturday 7 September 2013 14.34 EDT
First published on Saturday 7 September 2013 14.34 EDT

The American ambassador to Britain has issued a strong defence of the "special relationship", denying that it has been damaged by a vote in the Commons against the UK's participation in a military strike on Syria.

Writing in the Observer ahead of a visit to Britain by US secretary of state John Kerry, Matthew Barzun, who took up his ambassadorship two weeks ago, described the "rush to declare this relationship dead, damaged, or diminished" as "strange" and lacking in perspective.

He described Kerry's talks with William Hague as "evidence that our indispensable partnership is intact" and "that Britain remains an essential part of the international community's response to the crisis in Syria". Barzun's comments, his first major political intervention since his appointment, came after President Barack Obama issued a direct appeal to the American people and to Congress to back limited military strikes on Syria during his weekly address.

"The world is witnessing an extremely serious humanitarian crisis in Syria," writes Barzun. "But, regrettably, it's not the first and won't be the last. We are discussing how the international community should respond, proportionally and meaningfully, to the unconscionable and illegal use of chemical weapons. And that discussion is not over. That we are having it in an open and public way is a far better measure of our special relationship's health than any single vote.

"Debate and disagreement have always been features of the relationship between our two countries. What is more striking is that when there are differences of opinion, these do not damage or undermine the inherent strength of our partnership. President Obama provided perspective of his own on Friday when he urged us to remember that President Roosevelt had to overcome great congressional and public reluctance for America to become militarily involved" in the second world war.

With only a fragile coalition in favour of action against the regime of Bashar al-Assad from the G20 meeting in Russia, US officials have been working overtime to try to build support. "The UK," said Barzun, "has been especially valuable in building support among EU countries and in aggressively pursuing tough sanctions to deny funding and weaponry to the Assad regime."

Baroness Ashton, the EU's representative for foreign affairs, said yesterday the chemical attack was a "blatant violation of international law, a war crime and a crime against humanity".

Her remarks came as Obama began a week of planned appeals over the head of Congress to the American people to attempt to persuade voters to support his call for limited strikes on Syria in retaliation for the alleged gassing of hundreds of civilians on the outskirts of Damascus on 21 August.

In his weekly address he insisted: "What we're talking about is not an open-ended intervention. This would not be another Iraq or Afghanistan. There would be no American boots on the ground. Any action we take would be limited, both in time and scope – designed to deter the Syrian government from gassing its own people again and degrade its ability to do so.

"I know that the American people are weary after a decade of war, even as the war in Iraq has ended, and the war in Afghanistan is winding down. That's why we're not putting our troops in the middle of somebody else's war."

His remarks come at the beginning of a week in which Obama will make a second national address on Syria and in which the Senate will vote on the issue. They come, too, amid evidence that he has failed to persuade more than a handful of members of the House of Representatives of the wisdom of authorising force. "That's why I call on members of Congress, from both parties, to come together and stand up for the kind of world we want to live in; the kind of world we want to leave our children and future generations."

But in a telling indication of the mounting international concern over the prospect of US-led strikes, European foreign ministers urged the US to delay possible military action against Syria until UN chemical inspectors report. However, a senior state department official who attended Kerry's meeting with the ministers in Vilnius said Kerry made clear that the US has not made any decision to wait.